It is a constant challenge for communication systems to integrate technological improvements in order to remain competitive with later developed communication systems implementing more advanced technology. The problem is even more apparent in wireless communication systems that have large investments in previously installed infrastructure.
A communication system risks becoming obsolete if it does not incorporate system improvements. However, the implementation of new technology into a communication system typically accommodates legacy devices. One way of supporting legacy devices is to develop a parallel infrastructure for supporting the new technology while slowly phasing out the legacy infrastructure. As can be imagined, supporting two independent systems is a costly approach to providing legacy support. Another approach is to implement updates that are backward compatible with legacy devices. However, often, the architecture of the legacy devices creates a bottleneck for system improvements.
There is a constant challenge to implement improvements into wireless communication systems, while maintaining support for legacy devices.